Conventional self-cleaning type toilet seats, e.g., those having a ring-like shape, are typically mounted at a fixed position on a toilet bowl and incorporate a selected number of spray nozzles. The nozzles are usually supported by a box-like structure on a rear portion of the seat. The nozzles typically moisten substantially the entire upper surface of the seat, i.e., the surface that contacts the user's skin. After fluid spraying has been completed, the same nozzles then provide a stream of air to dry the seat.
Nozzle operation is controlled by a suitable electronic control system that utilizes sensors to determine when a use of the toilet has been terminated and, consequently, trigger the seat cleaning process in preparation for the next use.
The sanitizing fluid, which is usually stored in a tank or like reservoir, is sprayed onto the seat abundance, causing at least a portion of the fluid to drip from the seat edges, both inside and outside the ring. While drippage from the internal perimeter of the seat edge is not considered a problem, since the sanitizing fluid flows into the toilet bowl, dripping from the outer perimeter edge results in the entire external surface of the bowl being covered with fluid. This is because the external surface is not usually reachable by the drying air stream. Apart from creating the unpleasant impression of a lack of cleanliness, the user's clothing is often stained when it brushes against the excess fluid on the external bowl surface, this being undoubtedly annoying.
It has been also proposed to form a radial passage within the seat, in order to convey the excess fluid directly from the outer perimeter of the seat into the toilet bowl, as shown for example in U.S. Pat. No. 6,003,159, GB2275060 and GB1357249.